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Homework Help: Kinetic friction

  1. Mar 22, 2005 #1
    A 25.0 kg seal at an amusement park slides down a ramp into the pool below. The top of the ramp is 1.80 m higher than the surface of the water and the ramp is inclined at an angle of 30.0° above the horizontal. The seal starts from rest and reaches the water with a speed of 4.90 m/s.
  2. jcsd
  3. Mar 22, 2005 #2
    Im assuming you want to solve for the coefficient of friction. Draw a force diagram and identify all your forces and their magnitudes. From there, balance your Fx and Fy forces, and calculate what the final velocity would be without any friction.
    (hint: Final velocity with no friction = 5.52m/s)

    From there you know the difference in speed was 0.62m/s, so the force of friction accelerated you 0.62m/s in the opposite direction over the same distance. Using some kinematic equations,try find out the force of friction. Once you have that, divide by the normal force on the seal to get the friction coefficient.
  4. Mar 23, 2005 #3
    Need HElp

    The orbit of Halley's Comet around the Sun is a long thin ellipse. At its aphelion (point farthest from the Sun), the comet is 5.6 10^12 m from the Sun and moves with a speed of 13.0 km/s. What is the comet's speed at its perihelion (closest approach to the Sun) where its distance from the Sun is 8.4 10^10 m?
  5. Mar 23, 2005 #4

    You have posted on some one elses thread. Make sure you start a new thread.
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